This invention relates to adjustable strap apparatus. In one aspect, the invention relates to adjustable strap apparatus for holding open air foldable boat seats in a folded down position. In another aspect, the invention relates to foldable boat seats.
Fold-down or foldable boat seats are commonly used in fishing boats and other types of watercraft. The seat back of such seats is pivotally mounted to the seat base. A strap attached to the seat base is attachable to the seat back to hold the seat back firmly against the seat base when the seat is not in use. Maintaining the boat seat in the folded down position when the seat is not in use improves the aerodynamic properties of the boat when the boat is operated and towed and facilitates the placement of a cover on the boat.
In order to assure a proper match, the strap used to hold a foldable boat seat in the folded down position is usually made of the same material that is used to cover the seat, which is typically a vinyl material. A piece of the vinyl material is folded and sewn together, and snaps are installed on the ends thereof to fit corresponding snaps on the seat base and seat back. A piece of foam is sometimes inserted inside the strap to impart a degree of structural integrity to the strap.
Vinyl materials are tensile or ductile, that is, capable of being stretched or drawn out when tensile stress is applied thereto. Such straps do to have any elasticity and therefore do not recover their original shape after a deforming force has been removed. The permanent set or permanent elongation of the strap after it is stretched prevents the strap from maintaining the seat back tight against the seat base and negatively affects the aesthetics of the strap.
Unfortunately, normal operation and towing of the boat results in the application of significant stress to the strap when the strap is used to hold the boat seat in the folded down position. When fastened in place, the strap is pulled and stretched due to wind, waves, bumps in the road and so forth. For example, the constant flow of air on the front and top of the seat back puts tensile pressure on the seat strap. This concentrated force alone causes the seat strap to stretch, allowing the seat back to rise, causing more and more wind resistance and more and more stretching. Once a vinyl strap is stretched, it very quickly begins to look worn out and often cracks and tears. The increased wind resistance created by boat seats that are not held tightly in the folded down position decreases the performance and fuel efficiency of the boat or towing vehicle.
Due to the fact that the seat strap is made of the same material as the seat cover, the strap is not sold as a separate part. As a result, once the strap wears out, it is usually necessary to replace the entire seat. Since the replacement seat usually will not match the other seats in the boat, many boat owners end up replacing all of the seats in the boat, which can be expensive.
Thus, there is a need for a foldable boat seat strap that can be used to replace old, worn out seat straps without having to replace the entire seat. There is also a need for a foldable boat seat strap that does not quickly stretch and wear out due to normal use of the boat. Finally, there is a need for an improved adjustable strap apparatus that is useful in a variety of marine and other applications.